[email protected] (Kengo NAKAHARA) writes:
>Currently(after cryptosoft.c:r1.44), software encryption driver
>(swcrypto0) is initialized twice, that is, swcr_init() is called
>below two call paths.
> (1) swcrypto_attach()
> <= called from module initialization
> (2) swcryptoattach()
> <= called from autoconf(9) initialization
>Hmm, compare with pseudo interfaces like gif(4), It seems the
>swcryptoattach() should do nothing.
In this case, yes.
Modules have their own module info data structures compiled by the
linker, for a builtin module their modcmd function is called in
module_init_class().
pseudo devices have no bus attachment, their attach routines are
compiled by config(1) and called in config_finalize() after all
builtin modules have been initialized.
A run-time loaded module gets its modcmd function called much
later in module_load().
A modular pseudo device driver can take two paths:
1. augment pre-modular structure
xxxattach(num) {
/* do initialization as pseudo-device */
}
modcmd(cmd, arg) {
...
switch (cmd) {
case MODULE_CMD_INIT:
#ifdef _MODULE
/* do initialization */
#endif
break;
case MODULE_CMD_FINI:
#ifdef _MODULE
/* do finalization */
#endif
break;
...
}
}
2. replace pre-modular initialization
xxxattach(num) {
/* dummy */
}
modcmd(cmd, arg) {
switch (cmd) {
case MODULE_CMD_INIT:
/* do always initialization here */
break;
case MODULE_CMD_FINI:
/* do always finalization here */
break;
...
}
}
Most drivers chose the first path, because they need another initialization
for cdevsw/bdevsw which is handled by autoconf when the driver is builtin.
Only as a loaded module, the modcmd() has to handle this part.
3. augment pre-modular structure for a UNIX driver
xxxattach(num) {
/* do initialization as pseudo-device */
}
modcmd(cmd, arg) {
...
switch (cmd) {
case MODULE_CMD_INIT:
#ifdef _MODULE
/* do initialization */
/* devsw_attach */
#endif
break;
case MODULE_CMD_FINI:
#ifdef _MODULE
/* devsw_detach */
/* do finalization */
#endif
break;
...
}
}
--
--
Michael van Elst
Internet: [email protected]
"A potential Snark may lurk in every tree."
